Key matrix for a telephone handset



FIG. 1 is a front elevational view of a key matrix for a telephone handset showing our new design:

FIG. 2 is a lower front, right side perspective view thereof; and,

FIG. 3 is an upper front, left side perspective view thereof.

The dotted lines showing the outline of a telephone handset is for illustration purposes only and forms no part of the claimed invention. 

The ornamental design for a "key matrix for a telephone handset", as shown and described. 